Pre-hospital mechanical ventilation in septic shock patients

Abstract

Background: Mechanical ventilation can cause deleterious effects on the lung and thus alter patient's prognosis. The aim of this study was to describe the characteristics of prehospital mechanical ventilation in patients with septic shock requiring mechanical ventilation in the prehospital setting.

Methods: Patients with septic shock subjected to pre-hospital intubation and mechanical ventilation by a mobile intensive care unit were consecutively included and retrospectively analysed. Septic shock was defined according to the international sepsis-3 consensus conference. Patient's characteristics, interventions, prehospital ventilatory parameters and outcome were retrieved from medical records. The association between the tidal volume indexed on ideal body weight (VTIBW) and mortality at day 28 was evaluated.

Results: Fifty-nine patients were included. Septic shock was mainly associated with pulmonary (64%) infection. Mean pre-hospital VTIBW was 7 ± 1 ml.kg^-1 in the overall population. Mortality reached 42%. The AUC of VTIBW was 0.83 [0.72-0.94]. Using logistic regression model including: age, prehospital mean blood pressure, volume infused in the prehospital setting, FiO₂ and length of stay in the intensive care unit, the association with mortality remained significant for VTIBW (OR adjusted [CI95] = 4.11 [1.89-10.98]), VTIBW >8 ml·kg^-1 (OR adjusted [CI95] = 8.29 [2.35-34.98]) and VTIBW <8 ml·kg^-1 (OR adjusted [CI95] = 0.12 [0.03-0.43]).

Conclusion: In this retrospective study, we observed an association between mortality at day 28 and prehospital VTIBW in pre-hospital mechanically ventilated patients with septic shock. A VTIBW <8 ml·kg^-1 was associated with a decrease and a VTIBW >8 ml·kg^-1 with an increase in mortality.

Keywords: Ideal body weight; Mortality; Septic shock; Tidal volume.